How to share PHP sessions with PHP-FPM?

In order to share sessions between two sites using Fast-CGI, I had to edit their .php-fcgi-starter files and add "umask 0002" (I also had to remove "-d session.save_path=/var/www/clients/clientX/webX/tmp \" from one of the sites). (see http://www.howtoforge.com/forums/showthread.php?t=53392)